Physiography of India
Physiography: The study of physical features, processes, and stages of development of an area comes under physiography.
The main characteristic of Indian physiography is its vast, extensive, and great diversity in its physical features.
Physiographic division of India
India can be divided into the following six physiographic divisions:
- The Northern and North Eastern Mountains
- The Northern Plains
- The Peninsular Plateau
- The Indian Desert
- The coastal plains
- The Islands
The Northern and Northeastern Mountains
The northern and northeastern mountains consist of the Himalayas and North Eastern hills. A series of mountain ranges come under the Himalayas as such the great Himalayas or Himadri, the Middle Himalayas or Himachal, and the outer Himalayas or Shiwalik in the south.
The great Himalayan Mountain is also known as the central axial range, 2,500 km long from East to West, with width varying between 160-400 km North to South.
The Himalayas lies between the Indian sub-continent and the central and east Asian countries and acts as a geo-environmental divide. On the basis of geomorphological features, the Himalayas can be divided into the following sub-divisions:
- Kashmir or North-Western Himalayas
- Himachal and Uttarakhand Himalayas
- Darjeeling and Sikkim Himalayas
- Arunachal Himalayas
- Eastern Hills and Mountains
Kashmir or North-western Himalayas:
The Kashmir Himalayas is part of the Greater Himalayan Mountain in Kashmir. The North-eastern part of the Himalayas is a cold desert, that lies between Greater Himalayas and Karakoram ranges.
- Series of mountain ranges like Karakoram, Ladakh, Zasker and Pir Panjal come under Himlayas.
- Dal lake; the famous valley of Kashmir is situated between Greater Himalaya and Pir Panjal.
- Important freshwater lakes Dal Lake and Wular Lake, and Saltwater lakes; Pangong Tso and Tso Morii are also found in this region.
- Zafran; a local variety of saffron in Kashmir Himalayas is famous, cultivated in Karewas -the thick glacial clay deposits and other materials embedded with moraines.
- In the north-western Himalayas, important glaciers of South Asia like Baltoro and Siachen are found.
- Important Passes like Zozi La (Great Himalayas), Banihal La (Pir panajal), Photu La (Zaskar), and Khardung La (Ladakh range) found in this region.
- Famous pilgrimage places like Vaishno Devi, Amarnath cave, Chahar-e-Sharif, etc. are located in this region.
- Duns: (the longitudinal valleys) – The Southeastern part of this region consist of duns like Jammu dun, Pathankot Dun.
Himachal and Uttarakhand Himalayas:
Himachal and Uttarakhand Himalayas lie in the states of Himachal Pradesh and Uttarakhand between the Ravi river in the West and Kali (a tributary of Ghaghara) in the east.
- This region is drained by two rivers system i.e. the Indus and its tributaries (Ravi, Beas, and Sutlej), and the Ganga and its tributaries (the Yamuna, Ghaghara).
- The Himachal Himalayas is extended to its northeastern part Ladakh cold desert which lies in the Spiti sub-division of district Lahul and Spiti.
- All three Himalayas are prominent in this region; The great Himalayan range, the Lesser Himalayas (Dhaoladhar), and the Shiwalik range from north to south.
- Some important hill stations in Himachal Pradesh: Dharamshala, Shimla, Kausani, etc.
- Cantonment town and health resorts in Uttarakhand: Mussoorie, Almora, Ranikhet, Kasauli, Lansdown, etc.
- Some important duns of this region: Dehradun, Harike Dun, Kota dun, Chandigarh –Kalka Dun, Nalagarh Dun located in Shiwalik ranges.
- The Bhotias: the nomadic groups that live in the valleys in the Great Himalayas move between Bugyals (summer grassland on higher hills) during summer months and return to the valley during winter.
- Pilgrimage places in this region: Gangotri, Yamunotri, Kedarnath, Badrinath, Hemkund sahib, etc.
- Famous valley of flowers situated in this region.
- In Himachal and Uttarakhand Himalayas; Dev Prayag, Rudra-prayag, Karnaprayag, Nandaprayag, and Vishnuprayag is located. The Prayagas are sacred places of Hindus.
Darjeeling and Sikkim Himalayas
The Darjeeling and Sikkim Himalayas is relatively small, it is a significant portion of the Himalayas are between Nepal Himalayas (west) and Bhutan Himalayas (East). Fast-flowing rivers like Tista are prominent here. High Mountain peak Kanchenjunga is in this region.
- In this region, tea plantation is introduced by the British in this region because of suitable conditions for its growth like moderate slope, thick soil cover with high oceanic content, well-distributed rainfall throughout the year, mild winters.
- In this region duar formations are important. The duar formations are flood plains, these are important as they are used for developing tea gardens.
- Tribes in this region: Lepcha tribes live in higher reaches of this region, and in the Southern part mainly Darjeeling Himalayas, the mixed population of Nepalis, Bengalis, and tribals of Central India lives together.
- This region is known for its rich flora and fauna scenic beauty, and various types of orchids.
The Arunachal Himalayas lies between the East of Bhutan up to Diphu pass in the East. These Himalayas run in the South-west to North-East direction.
- Many important mountain peaks are located in this region, some of them are Kangtu, and Namcha Barwa.
- The river Brahmaputra flows through a deep gorge after crossing the Namcha Barwa peak.
- The other important fast-flowing perennial rivers are the Kameng, the Subansiri, the Dihang, the Dibang, the Lohit which form deep gorges and have the highest potential to produce hydro-electric power.
- Jhumming cultivation is a prominent practice in this region by ethnic tribal communities.
- The inter-valley transportation in the Northern part is nominal due to rugged topography.
Eastern Hills and Mountains
The Eastern Hills and Mountains lie on the extreme Eastern edge of India from North to South direction. The different names of these hills in the locality as Patkai Bum, Naga Hills, the Manipur Hills in the North, and Mizo and Lusai hills in the South.
- The unique physiography of Manipur is Loktak Lake, it is at the center surrounded by Mountains from all sides.
- Mizoram is also known as the Molasses basin made up of soft unconsolidated deposits. The Barak (tributary of Meghna) river is an important river in Manipur and Mizoram.
The Northern Plains
These plains are formed by the alluvial deposits or the sediments brought by the rivers, the Indus, the Ganga, and the Brahmaputra along with their tributaries. These plains are 3200km in length from the East to West, Width varies between 150-300 km and the maximum depth of its alluvial deposits varies between 1000-2000m.
The northern plains can be divided into three zones on the basis of the size of sediments:
- the Bhabar
- the Tarai and
- the Alluvial plains
Bhabar: It is a narrow belt of 8-10 km parallel to the foothills of Shiwalik. It is covered by heavy rock materials and boulders due to the breakup of the slopes, and river deposits.
Tarai: It is a 10-20 km wide zone in the south of the Bhabar belt is known as the Tarai belt. The Tarai zone is suitable for the thick growth of natural vegetation and varied wildlife.
Alluvial Plains: The alluvial plains further divided into Bhangar and Khadar.
- Bhangar: Old alluvial deposits are known as bhangra.
- Khadar: New alluvial deposits are known as khadar.
These plains consist most fertile soil suitable for the cultivation of a variety of crops like wheat, rice, sugarcane, jute, etc.
- Brahmaputra plains consist of a large number of riverine islands and sandbars. The river flows from northeast to South-west direction in the states of Arunachal Pradesh and Assam and enters into Bangladesh at Dhubri with the Southward turn at almost 90°.
- The mouth of these rivers forms some of the largest Delta in the world, for example, Sundarbans Delta.
The Peninsular Plateau
The peninsular plateau is one of the oldest and the most stable landmass of India. This plateau is triangular-shaped, irregular place rises from the height of 150 m above the river plains.
The peninsular plateau is surrounded by Delhi ridge in the North-West (extension of Aravalli hills), Rajmahal hills in the East, Gir range in the West, and Cardamom hills in the South.
- Its extension is also seen in the Northeast in the form of Shilong and Kabri-Anglong plateau.
- The Peninsular plateau is formed by a series of patland plateaus. The patland plateaus are made up of lava deposits. example- Hazaribagh, Palamu, Ranchi, Malwa, Coimbatore, and the Karnataka plateaus.
- The elevation of the plateau is between 600-900 m from the west to the east. Most of the rivers flow towards the Bay of Bengal.
- The Bhima fault in the plateau is important because of recurrent seismic activities.
- The Peninsular plateau consists of some important physiographic features like tors, block mountains, rift valleys, bare rocky structures, spurs, a series of hummocky hills, and wall-like quartzite dykes.
- In the Western and North-western parts, it also consists of black soil.
Complex relief of gorges and ravines are present in the Northwestern part. example- Ravines of Chambal, Bhind, and Monera, etc. The plateau can be divided into three groups on the basis of relief features:
- The Deccan Plateau
- The Central Highland
- The North-eastern Plateau
The Deccan Plateau:
Deccan Plateau is volacanic plateau. The Deccan plateau is bordered by the western Western Ghats in the west and the Eastern Ghats in the east, The Satpura, Maikal, and Mahadeo hills in the North.
- The Western Ghats: It extends from the Tapi River in the North to Kanyakumari in the South. The ghats are also known as Sahyadri in Maharashtra, Nilgiri hills in Karnataka and Tamil Nadu, Anaimalai and Cardamom hills in Kerala. The western ghats are more continuous and higher than the Eastern Ghats. The average elevation of this ghat is 1500m. the height increases from North to south.
- The Anaimudi (2,695m) is the highest peak in the Anaimalai hills and the Dodabetta (2,637m) is the second-highest peak of the peninsular plateau on the Nilgiri hills.
- Western ghats are the source of most of the Peninsular rivers.
- The Eastern Ghats: The ghat extends from the North-Eastern part of the Odisha to the Nilgiri Hills in the south.
- Some important ranges from North to South are Mhendragiri, Javadi, Palconda, Nallamala hills, etc.
The Central Highland:
The central highland extended through the North of the Deccan Plateau to Jaisalmer in the west. Longitudinal sand ridges and crescent-shaped sand dunes found in this area are known as barchans. It is an example of relict mountains which are highly denuded and form discontinuous ranges.
- In Central Highlands, the presence of metamorphic rocks such as marble, slate, gneiss, etc shows the process of metamorphic process in history.
- Vindhyan and Kaimur ranges are sources of most of the tributaries of the Yamuna river.
- The eastern extension of the central highland is formed by the Rajmahal hills. The mineral-rich Chotanagpur Plateau lies in the south of Rajmahal Hills.
The North Eastern Plateau:
The region includes Meghalaya and Karbi Anglong plateau (Assam), which is detached from the main Peninsular block due to the force of North Eastward movement of the Indian plate at the time of origin of the Himalayas.
- The Meghalaya plateau is subdivided into the Garo, the Khasi, and the Jayantia hills. These hills are named after the tribal groups in this region.
- The Meghalaya plateau is rich in mineral resources like coal, iron ore, limestone, uranium, sillimanite, etc.
- The surface is a highly eroded Meghalaya plateau, Cherrapunji consists of a bare rocky surface devoid of any permanent vegetation.
The Indian Desert
The Thar or Great Indian Desert lies to the North – West of the Aravali hills. The region consists of longitudinal dunes and barchans. This land is undulating (not leveled surface) topography. Because of its arid climate, it is also known as Marusthali, with low vegetation due to low rainfall (below 150mm per year).
- It is believed that the region was undersea during the Mesozoic era. The evidence can be seen by the wood fossils park at Akal and marine deposits around Brahmsar near Jaisalmer.
- The approximate age of the wood fossil is estimated to be 150 million years.
The desert area has two regional parts:
- The Northern part slopes to the west or Sindh
- The Southern part slopes towards the South or the Rann of Kachchh.
Rivers of this region: Most of the rivers of this region are ephemeral or seasonal, for example; the Luni river in the Southern Part.
Due to low rainfall and high evaporation, the part is a water-deficit region, the streams are seasonal from inland drainage, by joining a lake or playa. These lakes consist of brackish water, it is the main source of salt but unfit to drink.
The Coastal Plains
The region consists long coastline along the Arabian Sea and the Bay of Bengal. On the basis of location and geomorphological processes the coastal plains have been divided into two parts:
- The Western Coastal Plains
- The Eastern Coastal Plains
The Western coastal plains: These are submerged coastal plains, that extend from the Gujarat coast in the North to the Kerala coast in the South. It has been divided into four parts from north to south- The Kachchh and Kathiawar in Gujarat, the Konkan coast in Maharastra, Goa, and Malabar coast in Karnataka and Kerala respectively.
The Malabar coast has many Kayals (backwaters) that are used for fishing, and inland navigation and attract tourists due to their topography.
Eastern Coastal Plains: The eastern coastal plains are broader than the Western coastal plains, it is emergent coast. The rivers Mahanadi, Godavari, Krishna, and Kaveri, flow Eastward into the Bay of Bengal and form deltas here.
- Some ports located on the East Coast are Kolkata port, Haldia port, Ennore port, Tuticorin port, Visakhapatnam port, etc.
The Indian territory extends into the Arabian Sea and the Bay of Bengal in the form of Lakshadweep and Andaman and Nicobar Islands.
- Arabian Sea Island Group: It includes Lakshadweep and Minicoy islands situated between 8 ° North -12 degree North latitude and 71 ° east – 74 ° East longitudinal and located at 280-480 km off the Kerala coast.
- There are 36 islands of which 11 are inhabited. Minicoy is the largest with an area of 453 sq km.
- This group of islands is broadly divided by an eleven-degree channel, in North the Amini Island and South the Canannore Island.
- On the East Coast, the Archipelago is built of coral deposits and has storm beaches consisting of shingles, unconsolidated pebbles, boulders, and cobbles.
- The Bay of Bengal Island Group: This group of islands is divided into the Andaman (North) and Nicobar (South) separated by a water body called a ten-degree channel. It is situated between 6° N to 14 ° N Latitude and 92 ° E to 94 ° E Longitudes.
- There are 572 islands in this group.
- Barren Island is the only active volcano in India located on Nicobar Island.
- Some important mountain peaks in this region: Saddle (738m), Mt. Diavolo (515 m in middle Andaman), Mt. Koyob (460 m in South Andaman), Mt. Thuiller (642 m in Great Nicobar).
You can also read:
- Landforms and their evolution
- List of main volcanos of the world
- The Rocks- Igneous Rocks
- Sedimentary rocks
- Metamorphic rocks
- Location and Geological Divisions of India
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